early versus late deflation of distal tourniquet in ivra with and without ketorolac in hand & forearm surgery

Conditions: Hand Injuries With Intravenous Regional Anesthesia

Summary: bier block , or intravenous regional anesthesia (ivra), is a method of anesthesia for upper extremity surgeries. ivra was first described by august bier in 1908, and after a period of latency, it began to gain widespread use after holmes reemphasized its use in 1963. bier blocks are technically easy to perform, and the rates for successful anesthesia approach 98%. furthermore, when compared with brachial plexus blocks for outpatient hand and upper extremity surgery, ivra may realize lower costs and faster postanesthesia recovery. although a reliable source of anesthesia, ivra has been associated with some disadvantages. some patients cannot tolerate the tourniquet-mediated arm pain, and there are also reports of neurologic injury and compartment syndrome caused by the tourniquet. perhaps the most serious complications associated with ivra relate to the potential systemic toxicity of the local anesthetics used. if the local anesthetic gains access to a patient's systemic circulation, the central nervous system (cns) and cardiovascular system can be affected. the cns is usually affected first, with symptoms including dizziness, tinnitus, perioral paresthesia, and seizures. anesthetic-induced toxicity of the cardiovascular system may manifest as hypotension, bradycardia, arrhythmias, or cardiac arrest. historically, the tourniquet used in ivra is left inflated for a minimum of 20 minutes. theoretically, this allows time for the local anesthetic to bind to the tissues and, consequently, prevent a large bolus of drug from entering the systemic circulation. however, this tourniquet time appears to be arbitrary, and no safe time interval between anesthetic drug injection and tourniquet deflation has been established.

this is a prospective cohort , controlled , single-blinded , randomized study will be carried out at the department of anesthesia of sohag university hospital . this study will be conducted on 80 trauma patients who will be present for both elective and emergency hand and forearm surgery .. the patients will be allocated to one of four groups : early deflation occurs after 20 minutes of induction of ivra late deflation occurs after 40 - 60 minutes of induction of ivra * group one ( lidocaine or control le ) early deflation * group two ( lidocaine , ketorolac lke) early deflation * group three ( lidocaine or control ll ) late deflation * group four ( lidocaine , ketorolac lkl ) late deflation after establishing noninvasive arterial blood pressure, ecg, peripheral oxygen saturation monitoring, two venous cannulae will be inserted: one in a vein in the dorsum of operative hand and the other in the opposite hand for crystalloid infusion. the opposite arm will be elevated for 2 minutes, and using an esmarch bandage, the venous capacitance of the arm will be emptied. then, a double-pneumatic tourniquet will be applied. the proximal tourniquet will be inflated to a pressure of 250 mmhg and circulatory isolation of the arm will be confirmed by inspection, lack of radial pulse and failure of pulse oximetry tracing of ipsilateral index finger then esmarch bandage will be released.

Eligibility criteria:
inclusion criteria: * a normal healthy patient or a patient with mild systemic disease * aged between 20 and 70 years * male or female * schedueled for hand or forearm surgery exclusion criteria: * severe raynaud's disease (intermittent arteriolar vasospasm of the distal limbs after cold or emotional stimuli). * sickle cell disease (ivra is relatively contraindicated, unless meticulous exsanguination of the limb takes place prior to cuff inflation). * crush injury to the limb, ivra may provoke further tissue damage secondary to hypoxia. * patients should be fasting, as there may be a possibility of conversion to a general anaesthetic, alternatively the patient may require sedation in addition to ivra to improve co-operation. * psychic, uncooperative patients. * patient refusal.